There are many new features and retrofitted features from python 3.0 that will make the transition easier when it starts.

From the Python docs:

Python 2.7 is intended to be the last major release in the 2.x series. The Python maintainers are planning to focus their future efforts on the Python 3.x series.

This means that 2.7 will remain in place for a long time, running production systems that have not been ported to Python 3.x. Two consequences of the long-term significance of 2.7 are:

*

It’s very likely the 2.7 release will have a longer period of maintenance compared to earlier 2.x versions. Python 2.7 will continue to be maintained while the transition to 3.x continues, and the developers are planning to support Python 2.7 with bug-fix releases beyond the typical two years. *

A policy decision was made to silence warnings only of interest to developers. DeprecationWarning and its descendants are now ignored unless otherwise requested, preventing users from seeing warnings triggered by an application. This change was also made in the branch that will become Python 3.2. (Discussed on stdlib-sig and carried out in issue 7319.)

There were some issues with the last Python upgrade in Sublime 1.x, but if they've been sorted out, you might consider this.

The current plan is to move to 3.2 when it's released in February. Python 3.2 finally supports non-ascii module paths (!), which will make several things nicer for Sublime Text.

Moving to 2.7, while not too bad on Windows and Linux, would mean I'd have to stop using the system version of Python on OSX, and while that isn't too bad, I'm saving the headaches up for the 3.2 move.

jps wrote:The current plan is to move to 3.2 when it's released in February. Python 3.2 finally supports non-ascii module paths (!), which will make several things nicer for Sublime Text.

Moving to 2.7, while not too bad on Windows and Linux, would mean I'd have to stop using the system version of Python on OSX, and while that isn't too bad, I'm saving the headaches up for the 3.2 move.

I take it moving to 3.x was decided not to be worth it in the end?

I'm not intending to hassle you about it. Just found this old post and wondered what the final decision turned out to be.